The increasing adoption of smartphones and fitness devices creates an opportunity for collection of vast amounts of health and wellness data, including diet, physical activity, location, sleep, and symptoms. The ability for individuals or medical teams to make use of this data in ways that improve wellness or quality of healthcare, however, has not kept pace with the ability to collect it. We propose to apply contextual inquiry and user centered design to understand patient and provider attitudes, values, and aspirations for sharing patient lifelog data with medical teams. Such sharing has the potential to increase patient engagement and to support the medical team's guidance and decision- making. We will focus on how this data might be used to improve care for patients with irritable bowel syndrome (an example of a chronic disease) and patients who seek to maintain or reduce their weight (an example of preventive medicine). These two conditions have high individual and economic costs. Based on identified opportunities and values, we will iteratively develop and gather feedback on prototype summaries and visualizations. Finally, we will conduct a feasibility evaluation of the most promising approaches, in which we prepare summaries of actual patient data, make it available for use by providers, observe patient-provider interactions, and conduct semi-structured interviews. The end result will be prototype visualizations and summaries that use patient lifelog data to support IBS and weight loss/maintenance care, an understanding of patient and medical team concerns, aspirations, and values related to the use of such HIT systems, and generalized design principles for designing HIT systems that make patient lifelog data available to health providers. We will publish the design principles, our software for generating summaries, and design artifacts (e.g. low-fidelity prototypes). To accomplish this work; we have assembled a multidisciplinary team, including experts in human centered design and engineering, computer science, family medicine care, and gastroenterology. The project team has experience with contextual inquiry, user-centered design, and evaluation of health and wellness applications.